1. Field of the Invention
The present invention relates to an apparatus and method for performing initial network entry in a broadband wireless communication system. More particularly, the present invention relates to an apparatus and method in which a Mobile Station (MS) having a plurality of Media Access Control (MAC) addresses performs initial network entry without collisions in a system supporting multi-Frequency Allocation (FA) communication.
2. Description of the Related Art
Today, many wireless communication techniques are being proposed to achieve a high-speed mobile communication. Among them, an Orthogonal Frequency Division Multiplexing (OFDM) scheme is accepted as one of the most promising techniques for the next generation wireless communication systems. The OFDM scheme is expected to be widely used as a future wireless communication technique, and is currently used as a standard in the Institute of Electrical and Electronics Engineers (IEEE) 802.16-based Wireless Metropolitan Area Network (WMAN) known as the 3.5 generation technology.
The standard is being modified so that a communication system is being evolved to provide a high-speed data service in comparison with a legacy system or to address an implementation issue. In such a system evolution process, various systems may be present together in the same area according to a compatibility level with respect to the legacy system. For example, a new system further evolved from the legacy system may be installed in an area where an IEEE 802.16e system is installed. In this case, the new system has to be able to provide a service not only to a legacy Mobile Station (MS) but also to a new MS.
At present, an OFDM-base broadband wireless communication system has a structure which supports only an MS using a single bandwidth through one Frequency Allocation (FA). Therefore, in order to support a new MS using a wider bandwidth, which will be developed in the future, the FA used in the system needs to change to a new FA having a suitable bandwidth corresponding to the wider bandwidth. However, when the FA changes, the system cannot provide a service to a legacy MS using a narrow bandwidth. Therefore, there is a problem in that all legacy MSs have to be replaced while changing the FA used in the system. Accordingly, there is a need for a method which can support both the legacy MS using the narrow bandwidth and the new MS using the wide bandwidth in the process of evolving the wireless communication system.